Climate scientist is a broad description including atmospheric scientists and climatologists.
An atmospheric scientist studies the weather, climate and other aspects of the atmosphere to develop forecasts from their analyses of the data they collect. Atmospheric scientists use surface and air stations, weather balloons, sensors, satellites and radar. The information atmospheric scientists collect contributes to the understanding of air pollution, drought, the depletion of the ozone layer and other problems.
A climatologist is a specialised climate scientist who monitors and studies the climate and the factors that control its variability.
A climatologist may produce climate assessments and forecasts of seasonal conditions, or contribute to national and international assessments of climate variability and climate change. Climatologists may also provide relevant climate data to users such as the insurance industry.